Abstract: A satellite defends itself by having a plurality of corner cube retroreflectors with shutters, each having a laser light sensor. It is assumed that the attacker first must obtain positional and range information with a pulsed laser. When one of the sensors detects these low power laser pulses, it causes the shutter of the corner cube array to open and return the pulses with sufficient strength to saturate or damage the attack sensors.

Abstract: A photoconductive film reader comprises a disc with a read head attached to its bottom surface at an edge point and rotated over the photoconductive film at a sufficiently high velocity so that the read head floats aerodynamically on the film, the read head having means for sensing the information stored as electrostatic charge on the film. The film has a reset strip of a predetermined amount of charge prerecorded along one of its edges, resetting of the read head electronics being coincident with the passage of the read head over the reset strip. The floatation of the read head on the film reduces the effect of film modulations on the film-to-read head spacing and allows the spacing to be well defined and controllable.

Abstract: An improved laser pumping system is provided which utilizes optic fibers configured in a fan-in arrangement and an array of light emitting diodes or diode lasers to which the optic fibers are connected for concentrating light energy on a lasing medium. The improvement is an increase of the amount of light energy that can be applied to the laser within a fixed volume.

Abstract: A lens of an optical system in space is to be moved, and thereby be focused, resulting in the focusing of the system. The lens is mounted, in a diaphragm of resilient material, with a ring-like component made of magnetic material. An electromagnet is positioned on either side of the lens and of the ring-like component. Application of d.c. current, by remote control, through the electromagnets, causes the translational movement, and the necessary focusing, of the lens and, therefore, of the optical system.

Abstract: In a solid state, folded cavity, laser having a fundamental frequency and a second harmonic frequency, the efficiency of the laser is improved by placing a quarter wave plate, at the lower frequency, in the leg of the cavity containing the lasing element and positioning the quarter wave plate by angular rotation to compensate for any polarization discrimination to the laser rod gain.

Abstract: A far infrared laser having a CO.sub.2 laser gas cell located in the same optical cavity as the far infrared cell. The CO.sub.2 gas is made to flow through the CO.sub.2 cell within the laser cavity and the far infrared gas is made to flow in the far infrared cell within the laser cavity. The current is supplied between a pair of electrodes in the CO.sub.2 cell to excite the CO.sub.2 gas. The far infrared molecules are pumped by optical energy transfer from the CO.sub.2 laser radiation. The infrared radiation is removed by an aperture in one of the mirrors and a far infrared transparent window.

Abstract: A Nd:YAG laser operating in a dual functioning cavity with a Ba.sub.2 Na(NbO.sub.3).sub.5 frequency doubling crystal provides two frequencies of laser radiation, one frequency double the other, to provide a laser beacon beam at a wavelength of approximately 1.06 micrometers and a high data rate beam at a wavelength of approximately 0.53 micrometer.